Cholinesterase inhibitor to prevent falls in Parkinson’s disease (CHIEF-PD) trial: a phase 3 randomised, double-blind placebo-controlled trial of rivastigmine to prevent falls in P... oleh S. Neumann, J. Taylor, A. Bamford, C. Metcalfe, D. M. Gaunt, A. Whone, D. Steeds, S. R. Emmett, W. Hollingworth, Y. Ben-Shlomo, E. J. Henderson